Reservoir System for Gas Delivery to a Patient

ABSTRACT

An oxygen delivery system is provided that employs a reservoir for holding oxygen or an oxygen and medicine mixture while the patient is not inhaling. The reservoir generally prevents waste and reduces cost and helps prevent the patient from re-inhaling the previously exhaled gases.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. ProvisionalApplication Ser. No. 61/145,318 filed Jan. 16, 2009 entitled “ReservoirSystem for Oxygen and Medicine Delivery to a Patient,” the entirety ofwhich is incorporated herein by this reference.

FIELD OF THE INVENTION

The invention relates to a reservoir system designed to provide gas,such as oxygen or an oxygen and medicine mixture, to a patient.

BACKGROUND OF THE INVENTION

Gas is typically delivered to a patient by systems that generallyinclude a source, a mouth piece or mask and tubing interconnecting thesecomponents. “Gas” as used herein is comprised of compressed air, oxygen,helium and oxygen, a mixture of oxygen and medicine, or any other gasthat would typically be used for patient care, etc. The followingspecification is focused on oxygen or an oxygen/medicine mixture, whichwill be described in detail below, the use of “oxygen” is thus forexample only and does not limit the scope of the contemplated invention.To avoid a patient rebreathing his or her exhalation and, thus notreceiving a fresh or sufficient supply of oxygen and/or medicine, gasdelivery systems may also include a one-way valve to prevent exhaled airfrom mixing with the incoming supply of oxygen or aerosol mixture. Thepressure generated by the patient's exhalation is sufficient to closethe valve such that the exhalation vents through an outlet port. Thepressure generated by the patient's inhalation is sufficient to open thevalve, allowing the patient to breath in the prescribed oxygen oraerosol mixture.

Typically the oxygen source continuously outputs oxygen at apredetermined but variable rate or pressure. When the patient is notinhaling, oxygen continues to be delivered wherein the excess oxygen isvented to atmosphere through the outlet port and/or through the mouthpiece. Medicine may also be delivered to a patient through a similardelivery system. For example, a nebulizer may be added to the oxygendelivery system such that liquid medicine is aerosolized and mixed withthe oxygen flow. A nebulizer may also be used with a system that usesambient air, rather than oxygen, as the carrier for the aerosolizedmedicine. In either case, the same problem of waste exists. That is,when the patient is not inhaling, the aerosolized medicine continues tobe supplied by the oxygen source and the mixture (medicine plus ambientair and/or oxygen) is vented to the atmosphere. To account for the lossof medicine, health care providers typically over prescribe medicinedelivered by this method. Generally, a patient's inhalation accounts forapproximately one-third of the breathing cycle, with the remainingtwo-thirds being exhalation and dwell time. Thus, three times therequired dosage may be prescribed to accommodate system losses, which iswasteful and increases health care costs.

One attempt to solve the problem of waste has been to add a reservoirbag to the delivery system. The intended purpose of a reservoir bag isto capture the oxygen and/or aerosolized medicine that is deliveredduring those time periods when a patient is not inhaling, rather thanvent it into the atmosphere. When the patient does inhale, it isintended that the oxygen and/or aerosolized medicine stored in thereservoir bag is available to be inhaled, together with the oxygenand/or aerosolized medicine that is being continuously output from thesupply source. Accordingly, it is intended that less oxygen and/oraerosolized medicine is wasted and there is an available reserve ofoxygen and/or aerosolized medicine in the reservoir bag for the patientto inhale when the inhalation process starts.

Often reservoir bags are constructed of relatively thick walls andmaterial to provide durability to withstand damage in shipping, handlingand use. Due to the thick walled construction, the reservoir bag doesnot inflate well, if at all. More specifically, as the pressure requiredto inflate a thick walled bag is greater than the pressure required toopen the previously-discussed one-way valve, the pressurized oxygen willseek the path of least resistance and will be fed to the mask andultimately wasted. That is, the one-way valve opens without thereservoir bag being filled and the oxygen and/or medicine is vented toatmosphere through the outlet port rather than filling the reservoir.One ineffective response to this problem is to increase the pressure ofthe oxygen or aerosol delivery which would ideally inflate the bag.However, if the initial, lower pressure is sufficient to open theone-way valve, increasing the pressure will have the same effect. Evenif the reservoir bag opens as a result of the increase in pressure, oncethe one-way valve is open, the oxygen or aerosol mixture will vent toatmosphere instead of filling the reservoir. Moreover, increasing thepressure of the system results in a greater flow rate of the oxygenand/or aerosolized medicine which means more oxygen and/or aerosolizedmedicine will be lost through the outlet port than when the system wasoperating at a lower pressure. Another way to address this drawback isto reduce the size of the opening of the outlet port. Applicant ownsU.S. Pat. No. 5,613,489 directed to an outlet port valve with anadjustably sized opening, the entirety of which is incorporated hereinby reference. However, even if the outlet port is reduced in size, theone-way valve will inevitably open to allow oxygen or aerosol to escapethrough the outlet port.

Accordingly, there is a long standing and unresolved need to provide areservoir system for use with an oxygen or aerosol delivery systemwhereby a reserve of oxygen or an aerosolized medicine mixture iscreated in a reservoir when the patient is not inhaling, therebyeliminating or substantially reducing the waste of medicine and/oroxygen and ensuring the patient receives the prescribed dosage ofeach—without harming the patient.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a gas delivery system witha reservoir wherein internal system pressure requirements areestablished to cause the reservoir to fill or substantially fill whilethe patient is not inhaling. More specifically, one embodiment of thepresent invention employs a one-way valve with increased resistance.Further, resistance may be added to the system, such as by placing afilter, a throttle; decreased diameter tubing, or some other medicallyinert porous obstruction upstream of the outlet port. As used herein,“upstream” refers to a position closer to the gas supply and away fromthe patient. Still further, if an inflatable reservoir is used, thethickness of the walls of the inflatable reservoir may be reduced. Eachof these solutions, alone or in combination, will cause the reservoirbag to inflate and fill with oxygen and/or a mixture of oxygen/medicinesuch that a reserve is available for the patient, which will reducewaste. In one embodiment, the resistance to gas flow occurs before thegas reaches the outlet port of the delivery system. In other words, anystructure or component added, altered or selectively altered forpurposes of increasing the internal resistance to gas flow toward theoutlet port must not be positioned between the patient mouth piece andthe outlet port, otherwise the solution will be ineffective as theoxygen or aerosol will vent to atmosphere through the outlet port.Additionally, the internal system pressure may be adjusted relative tothe volume and rate of the patient's breath cycle such that thereservoir fills or is substantially filled prior to each inhalationcycle.

FIG. 1 is an example of a current commercial aerosol delivery system 10that does not employ a reservoir bag or one-way valving system. Oxygenor ambient air flows though supply tubing 12 and the nebulizer 14 andthe resulting aerosol mixture travels through housing 16 and mouth piece18 toward the patient, into tubing 20 or both, depending upon thedynamic internal system pressures. The mouth piece 18 may be replaced bya mask 14 as shown in FIG. 4. The tubing 20 may act as a reservoirwherein inhalation will draw gas from the tube 20, through the housing16 and to the mouth piece 18. The inhaled gas thus comprises the aerosolmixture from the nebulizer 14 and whatever gas is resident in the tubing20. On exhalation, the exhaled gases flow out through the mouth piece 18and housing 16 into the tubing 20 and ultimately into atmosphere throughoutlet port 22 of the tubing 20. During any period of time when thepatient is not inhaling, the aerosol mixture from the nebulizer 14 willflow toward the mouth piece 18 and toward the outlet port 22. Theportion of the aerosol mixture that flows toward the outlet port 22 willpurge at least some of the exhaled CO₂ that may be reside in the tubing20. However, if adequate flow sufficient to achieve a complete purge ofCO₂ from the tubing 20 is not provided, the patient may re-breathe theCO₂ residing in the tubing 20 upon subsequent inhalation. In addition,using the aerosol mixture for purging exhalation gases wastes medicationand reduces the prescribed volume of medication that is directed to thepatient, thereby requiring the dosage to be increased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exploded view of one embodiment of a currently availablecommercial gas delivery system, including a nebulizer.

FIG. 2 shows an exploded view of a first embodiment of the presentinvention, including a nebulizer.

FIG. 3 shows a housing employed by some embodiments of the presentinvention.

FIG. 4 shows an exploded view of an alternative embodiment of thepresent invention, without a nebulizer.

FIG. 5 shows an exploded view of a further alternative embodiment of thepresent invention.

FIG. 6 shows an enlargement of a non-inflatable reservoir with a one-wayvalve.

While the following disclosure describes the invention in connectionwith those embodiments presented, one should understand that theinvention is not strictly limited to these embodiments. Furthermore, oneshould understand that the drawings are not necessarily to scale, andthat in certain instances, the disclosure may not include details thatare not necessary for an understanding of the present invention, such asconventional details of fabrication and assembly.

DETAILED DESCRIPTION

Turning to FIGS. 2 and 3, a pulmonary drug delivery system 30 is shown.In general terms, the pulmonary drug delivery system 30 comprises a mainhousing 32, a patient interface port 33, such as a mouth piece 34,associated with the main housing 32, an reservoir port 36 associatedwith the main housing 32, a nebulizer 38 associated with the mainhousing 32, a gas source 40 associated with the nebulizer 38 andconnected thereto by appropriate tubing 42, and an inflatable/deflatablereservoir 44 associated with the main housing. The gas source 40 may bean oxygen tank, the hospital's oxygen source, a blender that isconnected to a combination of gas sources, an oxygen concentrator, acompressor, for example. For illustrative purposes, the gas source willbe an oxygen source for the following description. A connector 46 may beused to interconnect the reservoir 44 to the main housing 32, and a band48 or tape provides one option of sealing the reservoir 44 to theconnector 46. An oxygen line 42 is attached between the nebulizer 38 andthe source of oxygen or ambient air 40 and supplies the nebulizer whichcauses medication positioned in the nebulizer to be aerosolized andmixed with the oxygen or air for inhalation by the patient. As usedherein, the term “aerosolized mixture” will refer to a mixture ofmedicine and oxygen and/or air. A one-way valve 50 is installed in themain housing 32. A seat (see FIG. 3, #51) may be formed in the housing32 upon which the valve 50 is positioned. The valve 50 allows fluid,e.g., air, oxygen or an aerosolized mixture to flow to the patientthrough the mouth piece 34 but restricts exhaled air to flow into thenebulizer 38 or the inflatable reservoir 44. The valve 50 should be openfor the oxygen or aerosolized mixture to travel to the mouth piece 34.

The flow rate at which oxygen or air is supplied to the nebulizer is aknown amount and may be adjusted as required. In one embodiment, thepressure being delivered by the source is greater than the pressurerequired to open the one-way valve 50, but the flow rate of thepressurized oxygen or aerosolized mixture is decreased so that it takessome time for the pressure in the reservoir 44 and housing 32 to reach alevel that would open the valve 50. Accordingly, when a patient is notinhaling, the oxygen or aerosolized mixture exiting nebulizer 38 willaccumulate in the reservoir. At some point, however, the valve 50 willopen due to the pressure build up in the housing 32 and the reservoir44. If the patient is not inhaling at this time, the excess oxygen oraerosolized mixture will vent. Upon inhalation, the valve will open orremain open and allow the patient to receive the aerosolized mixture oroxygen from the nebulizer 38, as well as the supply of aerosolizedmixture or oxygen contained in the reservoir 44.

The flow rate of the aerosolized mixture or oxygen from the nebulizer 38should be adjusted to correspond with the patient's inhalation such thatthe volume of aerosolized mixture or oxygen that accumulates in thereservoir matches or nearly matches the patient's inhalation volumeintake, accounting for the volume of oxygen or aerosolized mixture thatwould also be simultaneously supplied from the nebulizer or oxygensource. Should the patient over-breathe and deplete the volume ofaerosolized mixture or oxygen in the reservoir, the patient may stillinhale the aerosolized mixture being generated by the nebulizer as wellas ambient air drawn through an outlet 52 or Positive ExpiratoryPressure (PEP) valve 53. When the patient exhales, the one-way valvewill close and all exhaled gas will exit through the PEP valve 53. Oneof skill in the art will appreciate that the exhaled gas may exit thoughanother outlet integrated into the housing 32, the mouth piece 34, themask (if applicable), etc. That is, the PEP valve is not necessarilyrequired for the contemplated invention to function. The PEP valve mayemploy a member 56 that is selectively rotated to control the flow offluid therethrough. In one embodiment the PEP valve 53 is used inconjunction with a filter mechanism 54 to filter exhaled gases, removecontaminants, bacteria, viruses and other contaminates for the safety ofhealthcare workers and others attending to the needs of the patient.During exhalation and any pause prior to the next inhalation, theaerosolized mixture or oxygen will inflate the reservoir 44.

To insure that the reservoir 44 fills, even in the case of patientsrequiring high flow rates, which requires higher internal pressurescould cause the one-way valve 50 to open prematurely, the resistance ofthe valve 50 may be increased. In one embodiment, a manually adjustablespring is used to alter the resistance of the valve 50. Alternatively,the one-way valve of increased resistance (not shown) may be placed inthe delivery system upstream of the PEP valve 53, i.e., between the PEPvale 53 and one-way valve 50. This second valve would compensate anunintended opening of valve 50. Further, resistance could take the formof one or more filters, some type of inert or non-harmful but porousobstruction, a throttle in the tubing, a throttle in the housing 32, atortuous air path, a flow path comprising flexible walls that expand andcontract with pressure changes, tubing with integrated pressure reliefcharacteristics (i.e., a hole covered by a flexible member that allowsgas to escape when the pressure of the gas reaches a predeterminedlevel), or a combination of one or more of these options. An importantfeature is that the internal resistance to gas flow toward the mouthpiece upstream of the PEP valve 53 is greater than that required to fillthe reservoir bag 44.

Referring now to FIG. 3, the housing 32 of one embodiment of the presentinvention is shown that includes a patient interface port 33, anebulizer port 39 and a reservoir port 36. The housing 32 also includesthe outlet 52 that is adapted to interconnect with the PEP device. Thevalve 50 is integrated into the housing 32 via an opening 55 in aportion of the housing 32. A cap 57 is also integrated to the opening toseal the housing 32. The valve 50 rests against a valve seat 51, whichmay be angled (α). The valve seat 51 will alter the pressure required toopen the valve 50 as a function of angle (α). More specifically, if thevalve is positioned vertically as shown, it will require less pressureto open if it is angled, for example, about 30 degrees, wherein theweight of the valve 50 must be additionally overcome to open the same.

FIG. 4 illustrates a non re-breather mask system incorporating anembodiment of the present invention. A patient mask 60 may have one ormore one-way valves 62 to prevent or control inhalation of ambient air.Alternatively, the mask 60 may have exit vents that are not valves orthe exhalation may simply escape around the peripheral edges of themask. A housing 64 is provided with a one-way valve 66 installed toprevent exhaled gas from entering the housing 64. A reservoir bag 68 maybe attached to the housing 64 with an attaching device 70 such as a bandtie or tape. The housing 64 also is interconnected to an oxygen line 72that is also associated with an oxygen or ambient air source 74.

When the oxygen source is turned on, pressurized oxygen will fill thereservoir bag 68 until the patient inhales. On inhalation, the valve 66opens and valve(s) 62 close causing all of the inhaled gases to comefrom the oxygen supply 74 and/or the reservoir 68. The flow of oxygenmay be adjusted to meet the patient's requirements. On exhalation, valve66 closes and valve(s) 62 open to allow the exhaled gas to escape fromthe mask and the reservoir bag 68 to refill with oxygen. A nebulizer(not shown) may be added between the housing 64 and the oxygen supplyline 72 and the system will work in the same way but the reservoir andpatient will be provided with an aerosolized mixture of oxygen andmedicine or ambient air and medicine.

With the current state of the art non-re-breather mask systems, thereservoir bag is stiff, as described above, and in order to fill thereservoir bag when the patient is not inhaling the pressure from theoxygen supply must be increased. However, the increased pressure alsocauses valves 62 and 66 to open causing at least some of the oxygen oraerosol mixture to exit out to atmosphere when the patient is notinhaling. Oxygen or aerosol mixture is thus wasted and the quantity ofmedicine or oxygen must be increased to accommodate the loss and toensure the patient receives the prescribed amount of medicine.

In one embodiment of the present invention the pressure required to openvalve(s) 62 and 66 is adjusted to require a pressure greater than thepressure required to substantially fill the reservoir 68 but is lessthan the pressure needed to open the valve 66 when the patient inhales.This assures the patient receives the prescribed oxygen level, requiresless oxygen flow to achieve the prescribed oxygen levels and reduces oreliminates the loss of oxygen or the aerosol mixture. The system of FIG.4 may also utilize the methods for adjusting system pressures describedabove in connection with FIG. 2.

Turning to FIGS. 4-6, a further embodiment of the present invention isprovided wherein the inflatable/deflatable reservoir shown in FIGS. 2and 4 is replaced with a rigid reservoir 80. Although this reservoir isprimarily intended for home or residential use, it can be used in anyenvironment, including hospitals, nursing homes and other institutions.The rigid reservoir 80 has the advantage of being more easily washed,cleaned and reused than an inflatable and deflatable reservoir.

In one embodiment, the rigid reservoir 80 includes an opening 82 at itsbase (on the right hand side as shown in FIG. 5). The opening 82 permitsambient air to be drawn into the reservoir. Similarly, if the mainhousing is not provided with a one-way valve of the type shown in FIGS.2 and 3, then the opening 82 may also act as an exit port when a patientis not inhaling. Accordingly, as the source of oxygen or aerosolizedmixture is filling the reservoir, the exit hole 82 permits any volume ofgas within the reservoir to be purged through the exit hole 82.

Alternatively, as shown in FIG. 6, a one-way valve 84 may be placed atthe opening 82 of the rigid reservoir 80 to permit the introduction ofambient air into the reservoir in an over-breathe situation and topreclude aerosolized mixture or oxygen from exiting from the reservoir.More specifically, a spring-biased valve is provided that is normallyclosed, i.e., the reservoir is closed, wherein the aerosolized mixturecannot escape from the reservoir 80. When the valve 84 is closed,however, the gas will vent through the PEP valve 53 and the reservoir 80will fill slowly. As the patient inhales and the pressure in thereservoir 80 reduces, the spring force will be overcome and the valve 84will open to let ambient air into the reservoir 80. During exhalation ordwell, the valve 84 will close to allow the reservoir 80 to fill: Inthis situation, it may also be desirable to place a one-way valve 86 inthe main housing 88 or associated with the patient mouth piece, forexample as shown in FIG. 3, such that exhaled air does not enter andcontaminate the main housing 88 and reservoir 80. As previously stated,the supply of oxygen and/or aerosolized mixture may be adjusted byadjusting the flow of oxygen from the associated oxygen source. Therigid reservoir may be blow-molded or manufactured in other ways knownto those skilled in the art from plastic such as polyethylene,polyvinylchloride (PVC) or flexible PVC.

Although the foregoing discussion concerning FIGS. 4-6 are directed to arigid reservoir, other embodiments of the present invention employ asemi-rigid, i.e., flexible reservoir. For example, the reservoir may becomprised at least partially of a material that reacts to a negativepressure associated with inhalation but maintains a predetermined shapewhen not exposed to a pressure variation. This “self-inflating”reservoir will thus return to its static shape in the absence ofexternal or internal pressure, similar to the bulb of a turkey baster,an eyedropper, an aspirator, etc. The material of manufacture of thecontemplated reservoir is any number of flexible plastics, for example,flexible PVC of a relatively thin wall thickness in the range of0.005-0.015 inches. As one of skill in the art will appreciate thecontemplated wall thickness would require adjustment depending on thematerial used. That is, the thicker the material the more memory thepart would have but the less likely it would deflate on inhalation. Inaddition, if the wall thickness is too thin it would not have enoughrigidity to be self inflating. One of skill in the art will appreciatethat the reservoir can be substantially rigid with a flexible portion,or a bellows, that allows expansion or contraction in response topatient breathing.

The contemplated reservoir would facilitate cleaning thereof as it willsubstantially maintain its shape when disconnected from the system asthe opening associated therewith may be oriented to allow drainage ofcleaning fluid. This aspect has an advantage over a substantiallycollapsible, less rigid bag that would prevent the escape of moisture,thereby promoting bacteria and or mold growth which reduces the lifeexpectancy thereof.

The present invention, in various embodiments, includes components,methods, processes, systems and/or apparatus substantially as depictedand described herein, including various embodiments, sub combinations,and subsets thereof. Those of skill in the art will understand how tomake and use the present invention after understanding the presentdisclosure. The present invention, in various embodiments, includesproviding devices and processes in the absence of items not depictedand/or described herein or in various embodiments hereof, including inthe absence of such items as may have been used in previous devices orprocesses, e.g., for improving performance, achieving ease and\orreducing cost of implementation.

The foregoing discussion of the invention has been presented forpurposes of illustration and description. The foregoing is not intendedto limit the invention to the form or forms disclosed herein. In theforegoing Detailed Description for example, various features of theinvention are grouped together in one or more embodiments for thepurpose of streamlining the disclosure. The features of the embodimentsof the invention may be combined in alternate embodiments other thanthose discussed above. This method of disclosure is not to beinterpreted as reflecting an intention that the claimed inventionrequires more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive aspects lie in less than allfeatures of a single foregoing disclosed embodiment. Thus, the followingclaims are hereby incorporated into this Detailed Description, with eachclaim standing on its own as a separate preferred embodiment of theinvention.

Moreover, though the description of the invention has includeddescription of one or more embodiments and certain variations andmodifications, other variations, combinations, and modifications arewithin the scope of the invention, e.g., as may be within the skill andknowledge of those in the art, after understanding the presentdisclosure. It is intended to obtain rights which include alternativeembodiments to the extent permitted, including alternate,interchangeable and/or equivalent structures, functions, ranges or stepsto those claimed, whether or not such alternate, interchangeable and/orequivalent structures, functions, ranges or steps are disclosed herein,and without intending to publicly dedicate any patentable subjectmatter.

1. In a gas delivery system for supplementing the breathing of apatient, a system comprising a patient interface device, a source ofpressurized gas, conduit for transporting gas from the source to themouth piece, an exhalation port disposed proximate the mouth piece andin fluid communication with at least one of the mask and the conduit,and an inflatable reservoir in communication with the conduit betweenthe gas source and the exhalation port, the improvement comprisingcreating resistance to gas flow between the inflatable reservoir and theexhalation port that is greater than the resistance to filling theinflatable reservoir with gas.
 2. The system of claim 1, wherein saidresistance is created by placing a one-way valve in the conduit betweenthe inflatable bag and the exhalation port.
 3. The system of claim 2,further comprising a spring associated with said one-way valve forchanging the resistance of the valve.
 4. The system of claim 3, whereinsaid spring is adjustable to alter the resistance of the one-way valveto opening.
 5. The system of claim 1, wherein said resistance is createdby placing a porous structure in the conduit between the inflatablereservoir and the exhalation port.
 6. The system of claim 5, whereinsaid porous structure comprises a filter.
 7. The system of claim 1,wherein said resistance is created by placing a throttle in the conduitbetween said inflatable reservoir and said exhalation port.
 8. A gasdelivery system, comprising: an oxygen source; a housing having aninlet, a first outlet, a second outlet and a third outlet, said housingincluding a valve that defines a first volume within said housingbetween the valve and the mouthpiece and a second volume between thevalve and inlet; a patient interface associated with said first outletof said housing, said valve being selectively openable when a patientinhales through said patient interface; a nebulizer associated saidinlet of said housing; an oxygen supply line associated with saidnebulizer and said oxygen source; a filter mechanism associated withsaid second outlet of said housing; a reservoir associated with saidthird outlet of said housing; and wherein said housing receives amixture of oxygen and medicine from said nebulizer that is directed tosaid reservoir, the mixture inflating said reservoir until said valve isopened, thereby allowing the mixture from said nebulizer and saidreservoir to exit said first opening.
 9. The gas delivery system ofclaim 8, wherein said patient interface is at least one of a mouth pieceor a mask.
 10. The gas delivery system of claim 8, wherein saidreservoir is rigid.
 11. The gas delivery system of claim 10, whereinsaid reservoir further comprises a valve.
 12. The system of claim 8,wherein said valve rests on a valve seat that is angled with respect toa longitudinal axis of said housing.
 13. A method of supplying oxygen toa patient comprising: providing an oxygen source; providing a housinghaving an inlet, a first outlet, a second outlet and a third outlet,said housing including a valve that defines a first volume within saidhousing between the valve and the mouthpiece and a second volume betweenthe valve and inlet; providing a mouthpiece associated with said firstoutlet of said housing, said valve being selectively openable when thethat selectively opens when a patient inhales through said mouth piece;providing a reservoir associated with said third outlet of said housing,said reservoir having a second valve; directing oxygen from said oxygensource to said housing; directing said oxygen to said reservoir; openingsaid valve when said patient inhales; opening said second valve whensaid oxygen in said reservoir is depleted; closing said first valve andsaid second valve when said patient is not inhaling.
 14. The method ofclaim 13, further comprising providing a nebulizer associated said inletof said housing wherein said reservoir receives a mixture of oxygen andmedicine.